Figure 1.

An illustration of the sequence of events within a trial. Following cue onset, participants covertly directed their attention toward either left or right hemifield marked by the 2 white dots, while maintaining eye fixation on the central dot. Targets were flashed briefly at one of the marked locations after a variable inter-stimulus interval. Participants were required to discriminate the spatial frequency of the gratings and make a forced 2-button choice response only when targets appeared on the attended location. At the end of each trial, participants were also prompted to report the hemifield they attended to. This reporting was necessitated by another condition of the experiment where the participants, upon seeing a “choice cue,” spontaneously decided which side to attend. Data from this choice condition was not analyzed here.